1. Field of the Invention
This invention relates to a wheelchair and more particularly to a wheelchair of such a construction that upon folding it becomes compact in both width and perimeter dimension.
2. Description of the Prior Art
Wheelchairs that are capable of adjustments have been available for many years. One of the first patents on such a chair issued in 1894 to Potter as U.S. Pat. No. 531,330. Subsequent to that folding wheelchairs became available to allow them to be placed in vehicles for transportation. An early such chair was illustrated and claimed in U.S. Pat. No. 2,095,411, issued Oct. 12, 1937 to Everest and Jennings.
The Everest and Jennings chair includes two side frames of tubular metal joined together by an X frame that includes a pivot point where the frame members cross. By pushing one side toward the other the chair could fold presenting a reduced width over the open extended width.
To this day the wheelchairs that fold, for convenience, all employ the X frame and some form of locking means to hold the chair open.
While the reduced width has been helpful, with the advent of smaller vehicles and the transportation of wheelchairs on aircraft the need for even further compactness has arising.
Further, the conventional wheelchair does not allow for the folding of the chair back and/or arms which again would increase the perimeter to such as the height of the folded chair. This can also affect its transportation in small vehicles with reduced interior height.
Up until the present there has not been a wheelchair capable of compact folding with a perimeter no greater than the diameter of the larger pair of wheels secured to the wheelchair.